As discussed in the previous section, the DSM-5 (APA, 2013) current diagnostic system relies upon a categorical classification system. In this type of diagnostic system, you either have a disorder or you do not. This method is quite suitable for certain types of disorders and conditions such as pregnancy. You either are pregnant, or you are not. It is less suitable and less accurate for other types of conditions. Unlike a concrete, absolute condition like pregnancy, personality is an abstract concept with many different dimensions in varying degrees. Many clinicians and researchers believe the personality traits associated with a particular personality disorder are best understood as extreme variants of ordinary personality traits that differ from what is considered average or ordinary, by degree, rather than a difference in type. This alternative way of viewing personality disorders is called a dimensional or continuous approach. In contrast to the categorical diagnostic system, a dimensional system views various personality features along a continuum.

Because of the many problems associated with a categorical method, various alternative dimensional models have been proposed. In this section we will discuss two such alternatives: 1) The DSM-5 dimensional model, and 2) Otto Kernberg's dimensional model.

Similar to the official, current DSM-5 categorical model of diagnosis, the proposed alternative dimensional model retains some of the same essential features of personality disorder diagnosis. First, in order to meet the proposed dimensional model's criteria there must be evidence of impaired functioning. In the dimensional model, the impairments are described in terms of impairment with respect to self, and impairment with respect to others. The second key feature is inflexibility. In other words, the impairments and personality traits are stable across a broad range of situations and across time. Therefore, both the official categorical diagnostic model, and the proposed dimensional model, both require significant impairment and inflexibility.

We are discussing a proposed, alternative model for personality disorder diagnosis offered in DSM-5 in the chapter called Emerging Measures and Models. It has two main dimensions: level of personality functioning and pathological personality traits.

Criterion A is divided into four aspects of personality functioning. These are: 1) identity, 2) self-direction, 3) empathy, 4) intimacy. Each is rated along a five point continuum, from zero (little to no impairment) then continuing on to some impairment; to moderate impairment; to severe impairment; to extreme impairment.

IDENTITY: This aspect of personality functioning represent a person's knowledge and awareness of self. A person with little to no impairment readily recognizes their own unique characteristics and accurately appraises these characteristics. They have a clear sense of their own boundaries and can experience, tolerate, and regulate a full range of emotions. In contrast, a person with impaired identity has varying degrees of difficulty with their sense of self. What awareness they do possess is likely to be inaccurate or distorted. Their boundaries with others are confused or lacking entirely. Emotions are fraught with problems including rapidly shifting emotions and/or difficulty regulating or tolerating emotions. At the extreme end of the continuum hatred and aggression may be the dominant affect. However, it may be denied or attributed to others.

SELF-DIRECTION: This aspect of personality functioning represents people's internal ability to establish and achieve reasonable expectations of themselves, personal goals, and standards of personal conduct. A person with little to no impairment sets realistic goals based on an accurate appraisal of strengths and limitations. Because of their ability to be self-directed, they can reflect on their own internal experiences and they generally attain fulfillment and satisfaction in life. In contrast, a person with impaired self-direction may become excessively preoccupied with personal goals to the exclusion of all else. Conversely, they may lack goals entirely. They may lack internal motivation and are instead motivated by external rewards or consequences. They may have a limited or absent ability to reflect on and understand their own internal processes. Life does not provide meaning and satisfaction. Instead, life may be experienced as pointless, or dangerous.

EMPATHY: Empathy is the ability to understand and consider another person's experience, including their thoughts, feelings, beliefs, and motivations. Someone with little to no impairment readily understands and accepts another person's experience, even when such an experience differs from their own. They accurately identify another person's motivations and they are acutely aware of how their own actions affect others. In contrast, an impaired person may have some limited ability to understand others' experiences but they may discount it as valid or important. Conversely, they may overly-attuned to others but only in a self-referential manner. They can be highly threatened by differences of opinion and they frequently misattribute their own destructive motivations to others. They have little to no ability to understand how their actions affect other people and may be bewildered or hostile when someone attempts to explain how their actions harmed another person.

INTIMACY: Intimacy refers to the desire and ability to form and maintain close, caring, meaningful, and reciprocal relationships. Someone with little to no impairment has the desire and skills needed to form and maintain multiple satisfying relationships. There is a desire for mutual cooperation and the ability to respond in a respectful and sensitive manner to other's ideas, emotions, and behaviors. In contrast, an impaired person lacks, in varying degrees, the desire and/or ability for form sustained meaningful relationships with others. Connections with others may be superficial and lack reciprocity. This person may cooperate with others but only for personal gain. In more extreme forms, relationships with others are valuable only to the extent they unilaterally provide some care, comfort, financial resources, or provide opportunities to demonstrate power and control by inflicting pain or suffering.